If you watch Ben Heck’s online show you’ll notice that the master modder has branched out beyond the gaming mods that made him famous. For his latest episode, Heck shows us how to make a very practical gadget: sunglasses that automatically raise or lower a pair of polarized clip-on shades depending on the ambient light.

Heck used an ATtiny board, a photo cell and a servo to modify his own sunglasses. Lesser mortals not versed in tinkering and programming will most likely zone out within two minutes of the clip; you can skip to about 11:55 in the video below if you’d just like to see the finished product.